Spark plug attachment for grounding sheathed wires



Dec. zo, 1966 R. G. LIVINGSTON SPARK PLUG ATTACHMEN1 FOR GROUNDINGSHEATHED WIRES Filed April 24, 1964 IN VENT 0R. 6. UWA/6570# Stfa Pgs @j,4 fram/.5y

United States Patent O 3,293,352 SPARK PLUG ATTACHMENT FOR GROUNDINGSHEATHED WIRES Russell G. Livingston, Los Angeles, Calif., assignortoHallett Manufacturing Company, Los Angeles, Calif., a corporation ofCalifornia Filed Apr. 24, 1964, Ser. No. 362,403 Claims. (Cl. 174-35)The present invention relates to a wire support and a sheath connectorfor sheathed ignition wires and more particularly to a device adaptedfor effecting a ground connection between a metallic sheath of a sparkplug wire so as to assist in the elimination of the transmission ofsignals causing interference or static in a radio in a motor vehicle.

Interference in two-way radios which are employed in automobiles and thelike and which transmit on the low frequency ranges is a problemparticularly when the receiver is some distance from the transmitter, sothat the broadcast signal is weak. Ordinarily, under such cir`cumstances it is necessary to shut off the engine to eliminate engineignition noise.

It is known that predominantly the engine ignition signals which causethe above noted interference emanate from the ignition wires.Accordingly, the present invention contemplates means for simply andeffectively connecting and grounding a metallic sheath or shield whichmay be disposed upon the ignition wire which extends between the engineignition distributor and the spark plugs.

The present invention contemplates a device mountable upon a spark plugso as to make a ground connection with the spark plug base, the deviceincluding means for connection to an end of the metallic sheath.

Obviously, the spark plug wire shielding may be grounded and anchored atits end remote from the spark plug by means of the support and groundingdevice as more particularly described and claimed in my co-pendingapplication filed concurrently herewith, Serial No. 362,404 entitledSheathed Ignition Wire Support and Sheath Connector.

In a specific sense, it is an object of the present invention to providemeans for clampingly and electroconductively engaging the hexagonalwrenching portion of a spark plug, said means carrying a `support armprojecting therefrom, the arm being bendable so as to assume any desiredinclination or disposition relative to the clamping means as may bedesired or necessary in connection with any given spark plug location asrelated to the location of the distributor from which the spark plugwire extends. This support arm has means at its outer extremity forenabling the anchoring of the end of a metallic shielding sheathextending along the spark plug wire.

Other objects and advantages of the invention will be hereinafterdescribed or will become apparent to those skilled in the art, and thenovel features of the invention will be defined in the appended claims.

In the accompanying drawing:

FIG. 1 is a view in perspective illustrating a spark plug attachmenthaving means for electroconductive anchorage of a metallic sheath, andmade in accordance with the present invention.

FIG. 2 is a longitudinal sectional view illustrating the spark plugattachment of FIG. l and showing in broken lines various positions whichmay be assumed by the support arm of the attachment and also showing inbroken lines a spark plug embraced within the attachment;

FIG. 3 is an enlarged fragmentary sectional view as taken on the line3-3 of FIG. 2;

FIG. 4 is a bottom plan of the assemblage of FIG. 2; and

FIG. 5 is a view generally corresponding to FIG. 2 but illustrating amodified form of the spark plug attachment.

Like reference characters in the several views of the drawings and inthe following description designate corresponding parts.

In the illustrative embodiment of FIG. 1, the spark plug attachment ofthe present invention is seen to comprise an elongated metallic member 1having at its lower extremity oppositely extended arcuate sections 2 and3 terminating in mutually confronted relation and defining therebetweena slot 4, and having at its upper extremity means for anchoring andelectroconductively connecting a metallic spark plug wire sheath to themember 1 and thence to a spark plug through the arcuate portions '2 and3.

As seen in FIG. 2, the arcuate portions 2 and 3 constitute means forgripping the hexagonal body portion 6 of a spark plug S. The attachmentis preferably comprised of sheet metal having resilience so that thearcuate portions 2 and 3 will normally be resiliently biased into tightengagement with the corners of the hexagonal plug portion 6.

The member 1 is of such length as to project upwardly beyond the upperextremity or cap 7 of the spark plug S and as shown in broken lines inFIG. 2 is adapted to be bent to any selected disposition relative to theclamping means and relative to the spark plug S so as to support thespark plug wire SW in a desired relation to the distributor from whichthe spark plug wire extends.

The sheath anchoring means previously referred t0 and as best seen inFIG. 3 in the embodiment thus far described, comprises a metallicgrommet 8 carried by an end flange 9 at the upper extremity of themember 1. The grommet and means for anchoring the end of the metallicsheath 10 to the grommet are the subject matter of the above notedco-pending patent application, but 1n general it will be noted that thegrommet is provided with an outer peripheral groove 11 into which an endof the sheath 10 which has been turned back about the outside of thegrommet is clamped by a split snap ring 12, the clamped end of thesheath and the grommet being encased within a rubber boot 13 whichclosely fits about the grommet and which has a section 14 which closelyfits upon the spark plug wire SW.

Referring to FIG. 5, it will be observed that this modified version ofthe spark plug attachment like that first described has an elongatedmember 1 and the clamping means comprising arcuate sections 2 and 3forming the slot 4 whereby the spark plug S is clampingly engaged asdescribed above. However, at its upper extremity the member 1 of FIG. 5is provided with means which anchor the end of the spark plug wiresheath 10, but otherwise the attachment affords no support for the sparkplug wire SW. In this embodiment the sheath 10 is in a known mannerprovided with a pigtail 10a by passing the spark plug wire SW through anopening formed by spreading apart the side wall of the mesh to form aspark plug wire opening. The pigtail 10a is secured electroconductivelyto the member 1 by fastener means 12a engageable with the end of thepigtail and with an out-turned end flange 9a on the member 1.

In each of the embodiments described, it is apparent that the member 1is sufficiently laterally displaced from the spark plug S as to precludearcing across the gap between the connector cap 7 of the spark plug andthe ground attachment, but in any event, the spark plug S is preferablycovered by a typical rubber boot 15 in each embodiment.

Inasmuch as the metallic base of the spark plug is threadedly engaged inthe cylinder head of an engine and inasmuch as the clamping means 2 and3 of the attachment are in electroconductive engagement with thehexagonal portion 6 of the spark plug While the member 1 iselectroconductively connected to the sheath 10, it will be apparent thatthe metallic sheath 10 will be eifectively grounded adjacent the sparkplug, while at its other end the sheath 10 may be grounded by connectionto the sheathed ignition wire support and sheath connector of the abovereferred to co-pending patent application. As a result,the groundedshielding sheath effectively shields the spark plug wire against thetransmission therefrom of signals which would otherwise result inobjectionable ignition noise in a radio forming part of the equipment ofa vehicle in which the spark plug is employed.

While 'specic structural detailshave been shown and described, it shouldbe understood that changes and alterations may be resorted to withoutdeparting from the spirit of the invention as defined in the appendedclaims.

I claim:

1. Shield means for grounding the metallic sheath of a spark plug wirecomprising in combination: a spark plug for an internal combustionengine and having a metal base; a wire connected to said plug forsupplying electrical energy thereto; an electrically conductive sheathon said wire; an elongate metal shield member having a length greaterthan that of said plug; said shield mernl plug; and metal clamp means onsaid other end of said arm engaging and making electrical connectionwith said sheath.

2. The shield means as set forth in claim 1, wherein said clamp means onsaid other end of said arm includes a grommet surrounding and supportingsaid wire.

3. The shield means as set forth in claim 1, wherein said arcuate clampincludes a pair of resilient arcuate members that terminate in mutuallyconfronting portions with a slot therebetween and engageable With saidmetal base of said plug.

4. The shield means as set forth in claim 1, wherein said armconstitutes means bendable at any point between its ends to dispose saidclamping means and said other end in different positions With respect tosaid plug best for effecting an electrical connection of said clampmeans to said sheath.

5. The shield means as set forth in claim 1, wherein said wire extendsthrough a side of said sheath, said sheath having a pigtail projectingfrom said wire and connected to said clamp means.

References Cited by the Examiner UNITED STATES PATENTS 2,730,562 l/l956Marden 174-35 3,128,139 4/1964 Estes 174-35 X FOREIGN PATENTS 324,402 l/1930 Great Britain.

LEWIS H. MYERS, Primary Examiner.

D. L. CLAY, Assistant Examiner.

1. SHIELD MEANS FOR GROUNDING THE METALLIC SHEATH OF A SPRAK PLUG WIRECOMPRISING IN COMBINATION: A SPARK PLUG FOR AN INTERNAL COMBUSTIONENGINE AND HAVING A METAL BASE; A WIRE CONNECTED TO SAID PLUG FORSUPPLYING ELECTRICAL ENERGY THERETO; AN ELECTRICALLY CONDUCTIVE SHEATHON SAID WIRE; AN ELONGATE METAL SHIELD MEMBER HAVING A LENGTH GREATERTHAN THAT OF SAID PLUG; SAID SHIELD MEMBER INCLUDING AN ELONGATE ARMHAVING AN ARCUATE METAL CLAMP FORWARD ON ONE END AND EXTENDING LATERALLYTHEREFROM AND EMBRACING THE METAL BASE OF SAID PLUG; SAID ARM EXTENDINGUPWARDLY FROM SAID CLAMP ALONG ONE SIDE OF SAID PLUG WITH THE OTHER ENDTHEREOF SPACED FROM SAID PLUG; AND METAL CLAMP MEANS ON SAID OTHER ENDOF SAID ARM ENGAGING AND MAKING ELECTRICAL CONNECTION WITH SAID SHEATH.